Robot control method, robot and computer-readable storage medium

Abstract

A robot control method includes: building a two-wheeled inverted pendulum model based on a wheel-legged robot; constructing initial state-space equations based on the two-wheeled inverted pendulum model; linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system; obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques.

What is claimed is: 
     
       1. A computer-implemented robot control method comprising:
 building a two-wheeled inverted pendulum model based on a wheel-legged robot; 
 constructing initial state-space equations based on the two-wheeled inverted pendulum model; 
 linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system; 
 obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and 
 solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques. 
 
     
     
       2. The method of  claim 1 , wherein controlling the wheel-legged robot according to the wheel torques comprises:
 using the wheel torques as control commands, and inputting the control commands into wheel motors of the wheel-legged robot; 
 controlling the wheel motors to output torques that are respectively equal to the wheel torques according to the control commands. 
 
     
     
       3. The method of  claim 2 , further comprising:
 obtaining a plurality of actual state variables of the wheel-legged robot after the wheel motors output the torques that are respectively equal to the wheel torques. 
 
     
     
       4. The method of  claim 1 , further comprising:
 performing forward kinematics analysis on a leg planar five-bar mechanism of the wheel-legged robot to obtain a system of equations for foot endpoints of the wheel-legged robot; 
 obtaining a foot endpoint vector expression according to the system of equations; 
 obtaining a velocity Jacobian matrix of a leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression; 
 determining a mapping relationship between the velocity Jacobian matrix, hip joint driving torque vectors and two-dimensional contact forces applied to the foot endpoints based on a principle of virtual work; 
 incorporating virtual spring-damper elements into the wheel-legged robot and establishing a feedback control framework; and 
 obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship, and controlling the wheel-legged robot according to the hip joint driving torques. 
 
     
     
       5. The method of  claim 4 , wherein obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship comprises:
 calculating the two-dimensional contact forces based on the feedback control framework; and 
 calculating the hip joint driving torques based on the calculated two-dimensional contact forces and the mapping relationship. 
 
     
     
       6. The method of  claim 5 , wherein incorporating virtual spring-damper elements into the wheel-legged robot and establishing the feedback control framework comprises:
 arranging the virtual spring-damper elements in a first direction and a second direction of the foot endpoints of the wheel-legged robot, as well as in a roll direction of the wheel-legged robot, to establish a three-channel feedback control framework. 
 
     
     
       7. The method of  claim 4 , wherein obtaining the velocity Jacobian matrix of the leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression comprises:
 performing total differential processing on the foot endpoint vector expression to obtain a total differential expression; and 
 determining the velocity Jacobian matrix according to the total differential expression. 
 
     
     
       8. A robot comprising:
 one or more processors; and 
 a memory coupled to the one or more processors, the memory storing programs that, when executed by the one or more processors, cause performance of operations comprising: 
 building a two-wheeled inverted pendulum model based on a wheel-legged robot; 
 constructing initial state-space equations based on the two-wheeled inverted pendulum model; 
 linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system; 
 obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and 
 solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques. 
 
     
     
       9. The robot of  claim 8 , wherein controlling the wheel-legged robot according to the wheel torques comprises:
 using the wheel torques as control commands, and inputting the control commands into wheel motors of the wheel-legged robot; 
 controlling the wheel motors to output torques that are respectively equal to the wheel torques according to the control commands. 
 
     
     
       10. The robot of  claim 9 , wherein the operations further comprise:
 obtaining a plurality of actual state variables of the wheel-legged robot after the wheel motors output the torques that are respectively equal to the wheel torques. 
 
     
     
       11. The robot of  claim 8 , wherein the operations further comprise:
 performing forward kinematics analysis on a leg planar five-bar mechanism of the wheel-legged robot to obtain a system of equations for foot endpoints of the wheel-legged robot; 
 obtaining a foot endpoint vector expression according to the system of equations; 
 obtaining a velocity Jacobian matrix of a leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression; 
 determining a mapping relationship between the velocity Jacobian matrix, hip joint driving torque vectors and two-dimensional contact forces applied to the foot endpoints based on a principle of virtual work; 
 incorporating virtual spring-damper elements into the wheel-legged robot and establishing a feedback control framework; and 
 obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship, and controlling the wheel-legged robot according to the hip joint driving torques. 
 
     
     
       12. The robot of  claim 11 , wherein obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship comprises:
 calculating the two-dimensional contact forces based on the feedback control framework; and 
 calculating the hip joint driving torques based on the calculated two-dimensional contact forces and the mapping relationship. 
 
     
     
       13. The robot of  claim 12 , wherein incorporating virtual spring-damper elements into the wheel-legged robot and establishing the feedback control framework comprises:
 arranging the virtual spring-damper elements in a first direction and a second direction of the foot endpoints of the wheel-legged robot, as well as in a roll direction of the wheel-legged robot, to establish a three-channel feedback control framework. 
 
     
     
       14. The robot of  claim 11 , wherein obtaining the velocity Jacobian matrix of the leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression comprises:
 performing total differential processing on the foot endpoint vector expression to obtain a total differential expression; and 
 determining the velocity Jacobian matrix according to the total differential expression. 
 
     
     
       15. A non-transitory computer-readable storage medium storing instructions that, when executed by at least one processor of a robot, cause the at least one processor to perform a method, the method comprising:
 building a two-wheeled inverted pendulum model based on a wheel-legged robot; 
 constructing initial state-space equations based on the two-wheeled inverted pendulum model; 
 linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system; 
 obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and 
 solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques. 
 
     
     
       16. The non-transitory computer-readable storage medium of  claim 15 , wherein controlling the wheel-legged robot according to the wheel torques comprises:
 using the wheel torques as control commands, and inputting the control commands into wheel motors of the wheel-legged robot; 
 controlling the wheel motors to output torques that are respectively equal to the wheel torques according to the control commands. 
 
     
     
       17. The non-transitory computer-readable storage medium of  claim 16 , wherein the method further comprises:
 obtaining a plurality of actual state variables of the wheel-legged robot after the wheel motors output the torques that are respectively equal to the wheel torques. 
 
     
     
       18. The non-transitory computer-readable storage medium of  claim 15 , wherein the method further comprises:
 performing forward kinematics analysis on a leg planar five-bar mechanism of the wheel-legged robot to obtain a system of equations for foot endpoints of the wheel-legged robot; 
 obtaining a foot endpoint vector expression according to the system of equations; 
 obtaining a velocity Jacobian matrix of a leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression; 
 determining a mapping relationship between the velocity Jacobian matrix, hip joint driving torque vectors and two-dimensional contact forces applied to the foot endpoints based on a principle of virtual work; 
 incorporating virtual spring-damper elements into the wheel-legged robot and establishing a feedback control framework; and 
 obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship, and controlling the wheel-legged robot according to the hip joint driving torques. 
 
     
     
       19. The non-transitory computer-readable storage medium of  claim 18 , wherein obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship comprises:
 calculating the two-dimensional contact forces based on the feedback control framework; and 
 calculating the hip joint driving torques based on the calculated two-dimensional contact forces and the mapping relationship. 
 
     
     
       20. The non-transitory computer-readable storage medium of  claim 19 , wherein incorporating virtual spring-damper elements into the wheel-legged robot and establishing the feedback control framework comprises:
 arranging the virtual spring-damper elements in a first direction and a second direction of the foot endpoints of the wheel-legged robot, as well as in a roll direction of the wheel-legged robot, to establish a three-channel feedback control framework.